Compositions containing vitamin A acetate or other vitamin A compounds are well-known in the prior art. However, in these compositions the vitamin A component is in neither crystalline nor microcrystalline form but rather in its oil form or in an oil-dissolved form. These preparations usually contain a protective colloid, such as gelatin. However, the stability of such products is limited since, at the required high vitamin A concentration, the oily vitamins readily pass through the protective colloid.
In other attempts to increase the stability of non-crystalline vitamin A compositions, antioxidants were added thereto. The presence of these antioxidants further reduced the applicability of these vitamin A compositions.
A process for the manufacture of dry preparations of vitamin A acetate in crystalline form is described in U.S. Pat. No. 2,643,209. The process involves the emulsification of crystalline vitamin A acetate in an aqueous gelatin solution. The emulsion is subsequently suspended in small droplets in mineral or vegetable oil and then cooled. In the resulting compositions, however, the vitamin A acetate is not in crystalline form.